Connecter



Patented Jan. 31, 1928.

UNITED STATES ALVIN D. Kamm, or PITTSBURGH, PENNSYLVANLA, AssrGNoRmo. Wns'rINGrHorIsn PTNTy vEIElC'LRIC & MANUFACTURING COMPANY, A CORPORATION 0F PENNSYLVANIA.

CONNECTER.

Application led July 6,

My invention relates to electric resistance conductors and particularly to connecters for such conductors.

One object of my invention is to provide a relatively simple and compact device for connecting the-ends of resistance conductors.

vAnother object of my invention is to provide a means forconnecting the ends of resistance conductors of relatively large area of ycross-section and of non-oxidizable material, that shall comprisea-member that changes. its crystalline structure and oxidizes upon initialfapplication of heat thereto,

causing it to increase in lateralarea, thereby tightly wedgingzthe conductors in place;

yIn practicing invention, I provide a tubular casing, of non-oxidizable material, located around the ends ofthe conductors and a membervthat oxidizesand changes its crystalline structure when initially subjected to relatively high' temperature, said memberbeing located within said casing and operatively engaging the I'ends ofthe conductors.

In .one modification of my invention, I

provide anl oXidiZable member in which a rust compound is placed to aidin establishinga relatively low resistance path Jfor the current from one vconductor Ito the other at thefirst yapplication of current thereto.

This rust compound may provide oxygen to aid in the oxidation ot the member.

In another modification of my invention,

lt provide a longitudinally slotted casing havingtaperingends, screw-threads on its Fig. 2 is a view, in end elevation, of a device embodying my invention, l

Fig. 3 is a view, in longitudinal section therethrough, taken on the line 1114-111 of Fig., 2, y

i923. serial No. 649,781.4

'Figf 4 is a view, in' end elevationfof af 4modified form of device embodyin'gmy invention, 1

Fig. 5 is a view,` in 'longitudinal lsection lherethrough, taken 'on ythe line V-'-V `of Fig. 6 aview,l in sidefelevation', of another modification,

Figf' isa view, in"later'al section therethrough, taken y'on thev li'ne Fis- G. l

Fig. 8 is ra view, in side elevation, of va still further modification, A

Fig. 9 is a view,'in 4lateral section therethrough, taken on thev line' Iii-IX 'of Fig. 10 is a` view, in sideelevation, of`a still further modification, 'i lFig. 11 is a view, in lateral section -therethrough, taken on the line 'Xl-'XI 'of Figaaand Fig. 12 is a view in lateral section of another form of conductor and'ofa device embodying my invention.

An electric yfurnace 21' is Y illustrated schematically inv Fig. 1k of 'the drawings las comprising a plurality of side, top .and bottom walls designated by the nu'irierai22. Each wall may comprise a pluralityl of'bricks or blocks of a suitable heat-insulating refractory material usually .employedin Ithe art, or it may comprise relatively large slabs of suchmaterial and may alsol comprise two layers as illustrated in the` drawing. 'The further details of'constructionfof ,the furnace structure are not illustrated 'as they form no part of my invention.

A heating elementfor the furnace comprises a resistor member 23ofrelativelyv heavy wire of nichrome or similar material,

that may be preformed to comprise a plurall ity of end-connected, substantially'paralleleXtending convolutions. The heating element may comprise a plurality of individual resistor members that are respectively connected by connecters" 24 embodying my invention and to be hereinafter described in detail The convolutions of the heating element may be supported in any suitable or desired manner withina' furnace chamber 25 enclosed by the walls 22. They sup orting means illustrated vin Fig. 1 of the' rawing comprises a plurality of spaced, elongated electric-insulating 'members' 2G that cooperate with the wall to which they are suitably secured to hold the` resistor member in its proper operative position within the f urnace chamber. The ends ofthe resistor member may be brought out through suitable bushings 27 in the walls of the furnace structure. As i the method of supporting, and.Y the method of bringing out the ends of theV resistor member constitute no part of my invention, they are not further illustrated or described in detail.

Figs. 2 and 3 illustrate a particular embodiment of my invention in which an outer tubular casing 28 of a nonoxidizable material such as nichrome has located therein a sleeve 29 'of oxidizable material such as steel or iron, Machine screws 31 are provided in the. casing 28 in order that the sleeve 29 may be securely held therein when the connecter is rst assembled in its proper operative position'in the ends of the resistance conductors.

The tubular casing 28 and the sleeve 29 are located over the adjacent or abutting ends of two resistor conductors 23. The sleeve 29 has an outer diameter that permits of its fitting closely within the casing 28 and the opening therethrough is of such lateral dimension as to receive the ends of the resistor, members 23 with what is usually termed a sliding lit.

The sleeve vof a connecter of the herein vbefore described construction, when subjected to relatively high temperature, undergoes a change of crystalline structure and it also oxidizes. Both of these changes cause it to swell, increasing its outer diameter and decreasing its inner diameter whereby it exerts a gripping action upon the non-oxidizable conductor ends located therewithin.

A plurality of radial holes 32 may be provided in the sleeve 29 distributed bot-l1 these 'holes before the assembly of the conlongitudinally and peripherally thereof, and a filling 33 of a rust compound is placed in necter. The rust compound may comprise? a mixture of iron filings and sal ammoniac or-a lead oxide.

When iron filings and sal 'ammoniac are employed, they quickly change into a red oxide of iron,'this change taking place within a relatively short timeafter the assembly of the connecter. As red oxide of iron is a conductor of electricity, it will aid in establishing a path of relativelylow electric resistance from one of the conductor ends to the other during the initial operation of the heating elemen The oxidizing action upon the steel or iron sleeve 29 causes the formation of a black oxide of iron which material is a good conductor of electricity. The lred oxide of iron produced by the iron filings and sal ammoniac inthe openings 32 is changed to a black oxide of iron, accompanied by a liberation .of oxygen thatfurther aids in causing oxidization of the sleeve 29.

Figs. 4 and 5 illustrate a modified form of the device embodying my invention. An outer casing 34 of non-oxidizable material is provided with tapering ends 35 and with a screw-threaded outer portion 36 located immediately adjacent to the tapering ends 35. The casing 34 is provided with a plurality vor' longitudinally extending slots 37 at eachend of the member 34.

A sleeve 29 of oxidizable material is located within the slotted casing 34 and has a sliding it`therein, Screw cap members 38 operatively engage the screw-threaded portions 36 and permit of tightly clamping the slotted ends of the casing 34 over the. ends of the sleeve 29, and also of clamping the outer ends of the sleeve 29 over the ends of the resistor members 23. This construction permits of obtaining good electrical contact between the ends of the resistors 23- and the surrounding sleeve 29 during the initial operation of the heating element of which these members constitute a part.

Figs. 6 and 7 illustrate another modification of the device embodying my invention and comprising a tubular casing 28 that is located over the ends 39 of a flat ribbon conductor that extend in the same direction into the casing 28. A bar 41, of iron or steel, substantially co-extensive with the casing 28 is located between the two ends of the resistance conductors 39, a machine screw 31 nol being provided to initially tightly clamp the 1" three members within the casing 28.

Upon subjection of the connecter tor a relatively high temperature, the crystalline structure of the member I41 changes and it also oxidizes, causing a swelling of themember 41 whereby the two conductors 39 are 'tightly wedged within the casing 28.

Figs. 8 and 9 illust-rate another modification of the device embodying my invention in which a non-oxidizable casing 28 extends 110 over the abutting ends of two round resistance conductors 23. The ends are provided with a longitudinally extending opening 42 and a longitudinally extending slot 43. A

member 44 of steel or iron, having'substan- 1 being subjected to a relatively high tem- 1' perature, substantially Vas hereinbefore described, to swell and tightly wedge the slotted ends ofthe resistor member 23 within the` casing modification in which the ends of the resistor members 23 are respectively provided with a longitudinally extending slot 43, within whichl an oxidizin 28. Figs. 10 and 11 illustrate a. still further 1 member 44, of bar shape, may be locate Upon application 139 f member in sa yof heat thereto, the member 44 swells, as

ber 44 of oxidizable material placed within the slot substantially as hereinbefore described. i

The device embodying my invention thus provides a relatively simple vand compact connecter that is eliective to provide a tight wedging joint between two conductors of a non-oxidizable material. `While I have illustrated a device as applying to a' relatively heavy resistor member, it is not restricted thereto, as itmay be employed to connect non-oXidizable resistance conductors of'relatively moderate diameter or of relatively small thickness.

Various modifications may be made inthe device embodying my invention without def parting from the spirit and scope thereof, and I desire that only such limitations shall be placed thereon as are imposed byJ the prior art, or are specifically set forth in the appended claims.

I claim as my invention: .t 1. A connecter for an electric conductor comprising a non-oxidizable casing surrounding theend of said conductor; and a id casing operatwely engaging said conductor, said member swelling permanentlyioy reason of changes in its crystalline structure and oxidation thereof upon the initial application of heat thereto and thereby wedglng the conductor tightly inI said casing.

2. A connecterfor the ends of non-oxidizable electric conductors comprising a nonoxidizable casing located over the ends of said conductors, and a sleeve of oxidizable material locatedwithin said casing and operatively engaging said conductors and swellf ingv permanently upon oxidization coincident with the heating thereof, wherebyr said conductors are tightly wedged in said casing. 3. A connecter for the ends of electric conduotors comprising a tubular casin having longitudinally slotted ends a s eeve of oxidizable material located withinl said cas-v ing and operatively engaging the ends otL said conductors, and means operatively engaging the'slotted ends of said casing forF clamping them tightly against said sleeve.

4. A connecter for electrical conductors comprising a casing, an oxidizable member therein connectin said conductors and means in said oxidlzable member for `supplying oxygen thereto, said oxidizable member consisting of a material which permanently expands radially, upon being heated, and wedges said conductors in said casing.

5. A connecter for electric conductors comprising an outer casing, a sleeve therein connecting said conductors, said sleeves comprising material that oXidizes upon the application of heatl thereto, and a means in said sleeve that provides oxygen to aid in vthe oxidation of said sleeve when heated.

6. A connecter for the ends of non-oxidizable electric conductors comprising a nonoXidizable casing located around the ends of said conductors, and a sleeve in said casing operatively engaging said conductor ends and comprising material that changes its crystalline structure and swells permanently upon the initial application of heat thereto whereby the ends of said conductors are tightl wedged in said casing.

7. connecter for the ends of electric conductors comprising a tubular casing of nonoxidizable material surrounding the ends of said conductors, and means located within said casing that swells permanently laterally of said casing upon the initial application of heat thereto, thereby tightly wedging said conductors in said casing.

8. A connecter for the ends of electric conductors comprising a tubular casing of nonoxidizable material surrounding the ends of said conductors, and means for automatically permanently wedging said ends in saidA casing upon .the initial application of heat thereto, said means comprising a material that changes its crystalline structure and permanently increases in area of cross-section when subjected to a relatively high temperature.

9. A connecter -for an electric conductor comprising a non-oxidizable encasing member and an oxidizable member therein that swells permanently upon being heated, for wedging said conductor insaid casing.

10. vA connecter for an electric conductor comprising a non-oxidizable encasing member for receivingthe end of said conductor and an oxidizable member in said structure that swells permanently upon being heated for wedging said conductor in said structure.

11. A connecter for an electric conductor comprising a non-oxidiza'ble means for receiving one end of said conductor and an ALVIN D. KEENE. 

